533  
FNCA52 TJSJ 170830  
FWFSJU  
 
FIRE WEATHER PLANNING FORECAST FOR PUERTO RICO  
NATIONAL WEATHER SERVICE SAN JUAN PR  
430 AM AST SAT APR 17 2021  
   
DISCUSSION
 
A SAHARAN AIR LAYER WILL CAUSE HAZY SKIES AND  
LIMITED SHOWER ACTIVITY ACROSS THE ISLANDS THROUGH THE WEEKEND.  
AN OVERALL DRYING TREND IS EXPECTED AND RELATIVE HUMIDITIES COULD  
REACH CRITICAL FIRE WEATHER THRESHOLDS TODAY AND ESPECIALLY ON  
SUNDAY. EAST TO SOUTHEAST WINDS COULD BRING SOME SHALLOW MOISTURE  
CONTENT EARLY IN THE MORNING HOURS ACROSS THE SOUTHERN AND  
EASTERN COASTAL AREAS OF PR TODAY, HOWEVER, DRIER CONDITIONS ARE  
EXPECTED DURING THE LATE MORNING AND EARLY AFTERNOON HOURS. WINDS  
TODAY SHOULD RANGE BETWEEN 10-15 MPH IN GENERAL, WITH HIGHER GUSTS  
DUE TO THE SEA BREEZE. THEREFORE, THERE IS AN ELEVATED FIRE DANGER  
POTENTIAL TODAY FOR THE SOUTHERN COAST OF PR.  
 
PRZ014-180830-  
SOUTHEAST COASTAL PLAINS-  
430 AM AST SAT APR 17 2021  
 
TODAY TONIGHT SUN  
 
CLOUD COVER MCLEAR MCLEAR MCLEAR  
PRECIP TYPE SHOWERS SHOWERS SHOWERS  
CHANCE PRECIP (%) 10 10 10  
TEMP (24H TREND) 87 (-2) 72 (-3) 89  
RH % (24H TREND) 55 (+5) 84 (-2) 46  
20FTWND-VAL/AM(MPH) E 9 E 10  
20FTWND-RDG/PM(MPH) SE 10 E 5 SE 11  
MIXING HGT(FT-AGL/MSL)5143 5254  
TRANSPORT WND (MPH) SE 13 SE 15  
VENT RATE (KT-FT) 53904 68402  
DISPERSION 5 5  
DSI 5 3 6  
LAL 1 1 1  
HAINES INDEX 3 4 3  
 
REMARKS...NONE.  
 

 
 
PRZ015-180830-  
SOUTHERN HILLS-  
430 AM AST SAT APR 17 2021  
 
TODAY TONIGHT SUN  
 
CLOUD COVER MCLEAR MCLEAR MCLEAR  
PRECIP TYPE SHOWERS SHOWERS SHOWERS  
CHANCE PRECIP (%) 10 10 10  
TEMP (24H TREND) 87 (+1) 70 (-1) 88  
RH % (24H TREND) 51 (0) 86 (-5) 45  
20FTWND-VAL/AM(MPH) SE 8 E 9  
20FTWND-RDG/PM(MPH) SE 9 SE 5 SE 10  
MIXING HGT(FT-AGL/MSL)6631 6612  
TRANSPORT WND (MPH) SE 12 SE 14  
VENT RATE (KT-FT) 63141 73951  
DISPERSION 5 5  
DSI 5 3 6  
LAL 1 1 1  
HAINES INDEX 3 4 3  
 
REMARKS...NONE.  
 

 
 
PRZ016-180830-  
NORTH COASTAL PLAINS-  
430 AM AST SAT APR 17 2021  
 
TODAY TONIGHT SUN  
 
CLOUD COVER PCLDY MCLEAR MCLEAR  
PRECIP TYPE SHOWERS SHOWERS SHOWERS  
CHANCE PRECIP (%) 30 10 10  
TEMP (24H TREND) 91 (+5) 72 (-3) 92  
RH % (24H TREND) 49 (-4) 85 (+1) 43  
20FTWND-VAL/AM(MPH) E 6 E 7  
20FTWND-RDG/PM(MPH) E 8 SE 5 E 10  
MIXING HGT(FT-AGL/MSL)6511 6251  
TRANSPORT WND (MPH) E 10 E 13  
VENT RATE (KT-FT) 71887 80201  
DISPERSION 5 5  
DSI 5 3 5  
LAL 1 1 1  
HAINES INDEX 3 4 4  
 
REMARKS...NONE.  
 

 
 
PRZ017-180830-  
NORTHERN HILLS-  
430 AM AST SAT APR 17 2021  
 
TODAY TONIGHT SUN  
 
CLOUD COVER PCLDY MCLEAR MCLEAR  
PRECIP TYPE SHOWERS SHOWERS SHOWERS  
CHANCE PRECIP (%) 50 10 20  
TEMP (24H TREND) 90 (+4) 69 (-3) 91  
RH % (24H TREND) 47 (-1) 89 (+2) 40  
20FTWND-VAL/AM(MPH) E 5 E 5  
20FTWND-RDG/PM(MPH) NE 6 LGT/VAR E 6  
MIXING HGT(FT-AGL/MSL)6860 7838  
TRANSPORT WND (MPH) SE 7 E 8  
VENT RATE (KT-FT) 48843 79417  
DISPERSION 5 5  
DSI 5 2 5  
LAL 1 1 1  
HAINES INDEX 3 4 3  
 
REMARKS...NONE.  
 

 
 
PRZ018-180830-  
WEST COAST-  
430 AM AST SAT APR 17 2021  
 
TODAY TONIGHT SUN  
 
CLOUD COVER MCLEAR MCLEAR MCLEAR  
PRECIP TYPE SHOWERS SHOWERS SHOWERS  
CHANCE PRECIP (%) 30 10 10  
TEMP (24H TREND) 89 (+2) 73 (-2) 91  
RH % (24H TREND) 52 (+1) 87 (+3) 46  
20FTWND-VAL/AM(MPH) E 7 E 7  
20FTWND-RDG/PM(MPH) SE 9 E 5 E 8  
MIXING HGT(FT-AGL/MSL)5646 5672  
TRANSPORT WND (MPH) SE 12 SE 13  
VENT RATE (KT-FT) 63635 77641  
DISPERSION 5 5  
DSI 5 4 6  
LAL 1 1 1  
HAINES INDEX 3 4 4  
 
REMARKS...NONE.  
 

 
 
PRZ019-180830-  
EASTERN INTERIOR-  
430 AM AST SAT APR 17 2021  
 
TODAY TONIGHT SUN  
 
CLOUD COVER PCLDY MCLEAR MCLEAR  
PRECIP TYPE SHOWERS SHOWERS SHOWERS  
CHANCE PRECIP (%) 20 20 10  
TEMP (24H TREND) 91 (+4) 70 (-2) 90  
RH % (24H TREND) 45 (-7) 87 (-6) 40  
20FTWND-VAL/AM(MPH) SE 7 SE 9  
20FTWND-RDG/PM(MPH) SE 10 SE 6 SE 10  
MIXING HGT(FT-AGL/MSL)7141 7269  
TRANSPORT WND (MPH) SE 12 SE 14  
VENT RATE (KT-FT) 69550 76103  
DISPERSION 5 5  
DSI 5 3 6  
LAL 1 1 1  
HAINES INDEX 3 5 3  
 
REMARKS...NONE.  
 

 
 
PRZ022-180830-  
LUQUILLO MOUNTAIN RANGE-  
430 AM AST SAT APR 17 2021  
 
TODAY TONIGHT SUN  
 
CLOUD COVER PCLDY PCLDY MCLEAR  
PRECIP TYPE SHOWERS SHOWERS SHOWERS  
CHANCE PRECIP (%) 30 20 10  
TEMP (24H TREND) 85 (+5) 67 (-2) 85  
RH % (24H TREND) 56 (-9) 90 (-8) 52  
20FTWND-VAL/AM(MPH) SE 8 SE 9  
20FTWND-RDG/PM(MPH) SE 10 SE 6 SE 10  
MIXING HGT(FT-AGL/MSL)4638 4984  
TRANSPORT WND (MPH) SE 13 SE 15  
VENT RATE (KT-FT) 49046 66861  
DISPERSION 5 5  
DSI 6 4 6  
LAL 1 1 1  
HAINES INDEX 3 5 3  
 
REMARKS...NONE.  
 

 
 
PRZ023-180830-  
CENTRAL MOUNTAIN RANGE-  
430 AM AST SAT APR 17 2021  
 
TODAY TONIGHT SUN  
 
CLOUD COVER PCLDY MCLEAR MCLEAR  
PRECIP TYPE SHOWERS SHOWERS SHOWERS  
CHANCE PRECIP (%) 30 10 20  
TEMP (24H TREND) 89 (+5) 67 (-2) 91  
RH % (24H TREND) 45 (-2) 89 (0) 39  
20FTWND-VAL/AM(MPH) SE 6 SE 7  
20FTWND-RDG/PM(MPH) SE 6 LGT/VAR SE 7  
MIXING HGT(FT-AGL/MSL)7247 8455  
TRANSPORT WND (MPH) SE 9 E 8  
VENT RATE (KT-FT) 61155 66590  
DISPERSION 5 5  
DSI 5 2 5  
LAL 1 1 1  
HAINES INDEX 3 4 3  
 
REMARKS...NONE.  
 

 
 
PRZ024-180830-  
CAYEY MOUNTAIN RANGE-  
430 AM AST SAT APR 17 2021  
 
TODAY TONIGHT SUN  
 
CLOUD COVER MCLEAR MCLEAR MCLEAR  
PRECIP TYPE SHOWERS SHOWERS SHOWERS  
CHANCE PRECIP (%) 20 20 20  
TEMP (24H TREND) 87 (+4) 69 (-1) 85  
RH % (24H TREND) 53 (-5) 85 (-12) 48  
20FTWND-VAL/AM(MPH) SE 8 SE 9  
20FTWND-RDG/PM(MPH) SE 10 SE 5 SE 10  
MIXING HGT(FT-AGL/MSL)5249 5381  
TRANSPORT WND (MPH) SE 12 SE 14  
VENT RATE (KT-FT) 56625 69523  
DISPERSION 5 5  
DSI 5 3 6  
LAL 1 1 1  
HAINES INDEX 3 4 3  
 
REMARKS...NONE.  
 

 
 
PRZ025-180830-  
VIEQUES-  
430 AM AST SAT APR 17 2021  
 
TODAY TONIGHT SUN  
 
CLOUD COVER PCLDY PCLDY MCLEAR  
PRECIP TYPE SHOWERS SHOWERS SHOWERS  
CHANCE PRECIP (%) 20 20 20  
TEMP (24H TREND) 86 (+1) 76 (0) 84  
RH % (24H TREND) 59 (-4) 81 (-7) 59  
20FTWND-VAL/AM(MPH) SE 11 E 11  
20FTWND-RDG/PM(MPH) SE 9 SE 8 E 11  
MIXING HGT(FT-AGL/MSL)2928 3906  
TRANSPORT WND (MPH) SE 9 SE 17  
VENT RATE (KT-FT) 24390 58590  
DISPERSION 5 5  
DSI 6 6 6  
LAL 1 1 1  
HAINES INDEX 3 5 4  
 
REMARKS...NONE.  
 

 
 
PRZ026-180830-  
CULEBRA-  
430 AM AST SAT APR 17 2021  
 
TODAY TONIGHT SUN  
 
CLOUD COVER PCLDY MCLEAR MCLEAR  
PRECIP TYPE SHOWERS SHOWERS SHOWERS  
CHANCE PRECIP (%) 30 20 20  
TEMP (24H TREND) 86 (+2) 76 (-1) 86  
RH % (24H TREND) 61 (-6) 81 (-6) 59  
20FTWND-VAL/AM(MPH) SE 13 E 12  
20FTWND-RDG/PM(MPH) SE 12 G19 SE 10 E 12  
MIXING HGT(FT-AGL/MSL)2971 3318  
TRANSPORT WND (MPH) SE 12 SE 17  
VENT RATE (KT-FT) 30094 50831  
DISPERSION 5 5  
DSI 6 6 6  
LAL 1 1 1  
HAINES INDEX 3 5 4  
 
REMARKS...NONE.  
 

 
 
PRZ027-180830-  
SOUTHWEST COASTAL PLAINS AND MONA ISLAND-  
430 AM AST SAT APR 17 2021  
 
TODAY TONIGHT SUN  
 
CLOUD COVER MCLEAR MCLEAR MCLEAR  
PRECIP TYPE NONE NONE NONE  
CHANCE PRECIP (%) 0 0 0  
TEMP (24H TREND) 88 (0) 73 (-3) 88  
RH % (24H TREND) 52 (0) 86 (+2) 47  
20FTWND-VAL/AM(MPH) E 11 E 11  
20FTWND-RDG/PM(MPH) SE 12 E 8 SE 12  
MIXING HGT(FT-AGL/MSL)5113 5199  
TRANSPORT WND (MPH) SE 17 SE 18  
VENT RATE (KT-FT) 69995 83429  
DISPERSION 5 5  
DSI 6 5 6  
LAL 1 1 1  
HAINES INDEX 3 4 4  
 
REMARKS...NONE.  
 

 
 
VIZ001-180830-  
SAINT THOMAS AND SAINT JOHN-  
430 AM AST SAT APR 17 2021  
 
TODAY TONIGHT SUN  
 
CLOUD COVER PCLDY MCLEAR MCLEAR  
PRECIP TYPE SHOWERS SHOWERS SHOWERS  
CHANCE PRECIP (%) 20 20 20  
TEMP (24H TREND) 85 (+1) 74 (-1) 85  
RH % (24H TREND) 60 (-4) 82 (-8) 59  
20FTWND-VAL/AM(MPH) SE 13 SE 13  
20FTWND-RDG/PM(MPH) SE 12 SE 9 SE 12  
MIXING HGT(FT-AGL/MSL)2857 3275  
TRANSPORT WND (MPH) E 10 E 18  
VENT RATE (KT-FT) 28040 52400  
DISPERSION 5 5  
DSI 6 6 6  
LAL 1 1 1  
HAINES INDEX 4 5 4  
 
REMARKS...NONE.  
 

 
 
VIZ002-180830-  
ST CROIX-  
430 AM AST SAT APR 17 2021  
 
TODAY TONIGHT SUN  
 
CLOUD COVER MCLEAR MCLEAR PCLDY  
PRECIP TYPE SHOWERS SHOWERS SHOWERS  
CHANCE PRECIP (%) 10 20 20  
TEMP (24H TREND) 86 (+1) 73 (-1) 86  
RH % (24H TREND) 55 (-7) 86 (-5) 56  
20FTWND-VAL/AM(MPH) SE 12 E 12  
20FTWND-RDG/PM(MPH) SE 11 E 9 E 11  
MIXING HGT(FT-AGL/MSL)4392 5101  
TRANSPORT WND (MPH) SE 16 SE 18  
VENT RATE (KT-FT) 58486 79390  
DISPERSION 5 5  
DSI 6 6 6  
LAL 1 1 1  
HAINES INDEX 4 5 4  
 
REMARKS...NONE.  
 

 
 

 
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab PR Page Main Text Page